Poly(arylene ether)s are a class of plastics known for excellent water resistance, dimensional stability, and inherent flame retardancy, as well as high oxygen permeability and oxygen/nitrogen selectivity. Properties such as strength, stiffness, chemical resistance, and heat resistance can be tailored by blending poly(arylene ether)s with various other plastics in order to meet the requirements of a wide variety of consumer products, for example, plumbing fixtures, electrical boxes, automotive parts, and insulation for wire and cable.
Injection molding compositions including a poly(arylene ether), a rubber-modified polystyrene, and a flame retardant are commonly used to mold a variety of articles. The melt rheology properties needed for injection molding these compositions are generally known. However, the present inventor has observed that injection molding compositions exhibiting similar melt rheology properties can exhibit different molding characteristics when used to mold articles having large, thin sections. For example, some molding compositions exhibit much larger mold shrinkages and/or warping than others. There is therefore a need to identify previously unrecognized melt rheology property limitations that improve the molding of large, thin objects from poly(arylene ether) compositions. This is also a need to identify poly(arylene ether) compositions that satisfy the previously unrecognized melt rheology property limitations.